Headrest system for a vehicle seat

ABSTRACT

The invention relates to a headrest system for a vehicle seat, said headrest system comprising a headrest ( 1 ) supported by at least one holding rod ( 3 ), a guide component ( 5 ), which can be arrested in the backrest ( 11 ) of the vehicle seat and serves for receiving a holding rod ( 3 ), a first electric connector disposed on the free end ( 10 ) of the holding rod ( 3 ) and a second electric connector, which cooperates with the first electric connector and can be arrested in the backrest ( 11 ), the joining direction ( 42 ) of the two electric connectors running approximately coaxially to the central longitudinal axis ( 19 ) of the free end ( 10 ) of the holding rod ( 3 ), and each of said two electric connectors comprising at least two contact elements designed in a rotationally symmetrical manner in relation to the central longitudinal axis ( 19 ) or the joining direction ( 42 ).

The invention relates to a headrest system for a vehicle seat, into which headrest system there is integrated an electrical device, for example, a motor used for pivoting the headrest. An electrical connection to the vehicle electrical system is required for supplying power to the electrical device. For this purpose, a cable section is laid in the backrest of the seat. The headrest can be coupled to the cable section with the help of a connector, which is disposed on the free end of a holding rod and a connector, which is disposed in the backrest, each of said connectors comprising at least two contact elements. In such systems that are disclosed, for example, in DE 10 2005 014 897, EP 0 858 929 A1, and DE 10 2004 007 325 B3, it must be ensured that the two connectors are disposed in a predefined rotational position in relation to their joining direction, thus the direction in which the connectors have to be moved relatively toward each other in order to join them together, or in relation to the central longitudinal axis of that free end of the holding rod that supports one connector. The connectors must therefore be arrested in a predefined rotational position on the holding rod or on a guide component, which receives the holding rod and is disposed in the backrest, or also on another component. This increases the costs of production and assembly and also involves the risk of a defective assembly.

It is the object of the invention to suggest a headrest system with simplified processes of production and assembly while eliminating the risk of a defective assembly of the connectors in the sense defined above.

This object is achieved in a headrest system of the type mentioned in the introduction according to claim 1 by designing the contact elements of the connectors in a rotationally symmetrical manner in relation to the joining direction and/or in relation to the central longitudinal axis of the holding rod. In the case of a connector designed as a plug, this is possible with low costs for production and assembly by using a connector which comprises a central contact pin, which extends in the joining direction and penetrates a contact sleeve, which has an electrical insulation on its inner side, the contact pin forming a first and the contact sleeve forming a second contact element. The contact sleeve can be held on the contact pin, for example, by friction. An electrical insulation between the contact pin and the contact sleeve can be easily implemented in the form of a sleeve, which is made of an electrically insulating material, for example, plastic, and which is fitted on the contact pin or is penetrated by the same.

A connector designed as a socket comprises a recess, which receives the contact pin and in which are disposed two contact sleeves, which are spaced apart in the joining direction, are electrically insulated from each other, and cooperate with the contact pin or the contact sleeve of the plug. Such a connector can likewise be produced with less expenditure, if, for example, the contact sleeves and optionally the connecting cables connected thereto are held by or embedded in an injection-molded plastic part. A connector that is arrested on a holding rod, be

it designed as a plug or a socket, is preferably disposed in a hollow space existing in the free end of the holding rod. This firstly ensures that the connector is easily arrested and secondly that the connector is provided with mechanical protection. The connector can be arrested in the hollow space with particular ease if a longitudinal section of the connector is provided with a design resembling a ribbed plug. If such a connector is inserted into the holding rod, the ribs anchored against the inner wall of the holding rod securely hold the connector in the holding rod.

The connector present in the backrest is either disposed such that it is stationary or is provided with variable height in the case of a height-adjustable headrest. In the former case, the connector is expediently arrested on the guide component by means of a snap-fit joint in such a way that when the holding rod is completely inserted into the guide component, the connector on the holding rod is properly connected to the stationary connector of the backrest. For example, due to manufacturing tolerances and inaccuracies in assembly there exists the risk that when the holding rod is inserted into the guide component, thereby joining the connectors, an undesirable force is applied to the connector present in the backrest. This involves the risk of the snap-fit joint between the guide component and the connector getting damaged or loose. In a preferred embodiment, this is prevented by arresting the connector on that end of the guide component that is turned away from the headrest by means of a snap-fit joint, the joining direction of which runs transversely to the central longitudinal axis of the holding rod or the joining direction of the connectors, and additionally

by means of an undercut, which is effective in the direction of said central longitudinal axis. A force acting on the connector thus stresses the structures forming the undercut and not the snap-fit elements. These structures can be provided with a substantially more stable and stress-resistant design than the snap-fit elements since they do not require to be flexibly deformable unlike a snap-fit joint. In the present case, the latter are solely used to laterally arrest the connector on the guide component or on another component of the backrest.

The undercut is preferably formed by an undercut element, which is present on that side of the connector that faces the guide component and which extends transversely to the joining direction of the connectors. This undercut element cooperates with a counter element, which is located on the guide component and is provided with a complementary design. Due to this design, the connector can be made to slide on the guide component laterally during assembly for enabling the production of the snap-fit joint. This enables the snap-fit joint and the undercut to be produced simultaneously. The undercut element and the counter element preferably cooperate in such a way that the connector can be arrested in any rotational position on the guide component depending on the installation circumstances. This is achieved in an advantageous embodiment, in which the undercut element is a circular ring-shaped flange, which projects from the peripheral surface of the guide component in the radial direction and the counter element is a groove, which is located on the connector and receives the flange.

Additional preferred embodiments are explained in the following description based on the enclosed figures, in which:

FIG. 1 is a partial sectional view of a headrest system comprising a headrest supported by two holding rods and a guide component disposed in the backrest, and two connectors, namely a socket and a plug,

FIG. 2 is a sectional view of the connectors shown in FIG. 1, the contact elements of the connectors being shown in the disassembled state,

FIG. 3 is a perspective view of a connector designed as a plug,

FIG. 4 shows a longitudinal section of a guide component. The plug shown in FIG. 3 is arrested on that end of the guide component that is turned away from the headrest,

FIG. 5 shows section V marked in FIG. 4.

The headrest system shown in FIG. 1 in its installed state is substantially composed of a headrest 1 comprising an impact body 2, two holding rods 3 (only one of which is shown in FIG. 1), which are interconnected by means of a transverse bar 4 disposed inside the impact body, a substantially tubular guide component 5, which is disposed in the backrest 11 of a vehicle seat, and is penetrated by a channel 6 receiving the holding rod 3 and two connectors, namely a socket 7 that is connected to the holding rod 3 and a plug 8 that is arrested on that end of the guide component that is turned away from the headrest 1. An electrical device (not shown) is present in the headrest 1. For connecting to a vehicle electrical system, two (or more) electrical cables 9 are led via the internally hollow transverse bar 4 and the likewise internally hollow holding rod 3 to the free end 10 of the latter or to the socket 7 disposed there.

The socket 7 comprises a substantially rotationally symmetrical plastic body, the outer diameter of which corresponds approximately to the inner diameter of the free end 10 of the holding rod 3. Several ribs 14 are formed on that longitudinal section 13 of the socket 7 that faces the headrest 1 and has a reduced diameter. These ribs 14 extend approximately in the radial direction and are anchored against the inner wall of the free end 10. In this way, the socket 8 is held in the holding rod 3. That region 15 of the holding rod 3 that receives the socket 7 is extended in the radial direction as compared to the remaining part of the interior of the holding rod, and merges into the latter with a radial shoulder 16. The radial shoulder 16 serves as an insertion limit stop for the socket 7. A central recess 18, which opens into the front side of the socket 17, is present in the socket 7. The recess 18 comprises two contact elements, namely a first contact sleeve 20 and a second contact sleeve 23, which are designed in a rotationally symmetrical manner with respect to the central longitudinal axis 19 of the free end 10 of the holding rod or the joining direction 12 [sic; 42] of the socket 7 and the plug 8. The diameter of the first contact sleeve 20 is larger than that of the second contact sleeve 23, the contact sleeves being disposed in the longitudinal sections 24 and 25 respectively, which are located in the recess 18 and have corresponding diameters, namely the first contact sleeve 10 [sic; 20] is disposed in the longitudinal section 24 and the second contact sleeve 23 is disposed in the longitudinal section 25. Those ends of the cable 9 that lead to the contact sleeves 20, 23 are embedded in the plastic body of the socket 7.

A connector designed as a plug 8 comprises a housing 26, which is made, for example, of plastic, and has a substantially cup-shaped design and accordingly a central recess 27, which is defined by an annular wall 28. A contact pin 30, on which an insulating sleeve 33 is fitted, projects centrally from the base 29 of the recess. A contact sleeve 34 is in turn fitted on the insulating sleeve 33. Said sleeves are shorter than the contact pin 30 so that the latter projects from the sleeves with a projecting end 35. In the assembled state (FIGS. 1, 5), the projecting end 35 of the contact pin 39 [sic; 30] penetrates the second contact sleeve 23 and the contact sleeve 34 penetrates the first contact sleeve 20 of the socket 7. For arresting the contact pin 30 on the housing 26, a cylindrical sleeve 36 projects from the base 29 of the recess 27. The cylindrical sleeve 36 receives that end of the contact pin 30 that is turned away from the socket 7. Cables 53 are connected to the contact pin 30 and the contact sleeve 34 of the plug 8. These cables lead laterally from the housing 26 so that the plug housing has a small overall height.

The annular wall 28 is divided into two wall sections 37, 38, each of which runs over an arc segment of 180°, the height 39 of the wall section 37 being greater than the height 49 [sic; 40] of the wall section 38 (FIG. 2). A projection 43 designed as a unilaterally open ring is formed on that upper side 41 of the wall section 37 that points toward the socket 7. The inner diameter 44 of the projection 43 is larger than the inner diameter 45 of the recess 27 of the housing 26. A groove 47 is inserted in the inner wall 46 of the projection 44 [sic; 43]. That side wall 48 of the groove 47 that points toward the socket 7 is flush with the upper side 41 of the wall section 37. The free ends 49 of the projection 43 extend beyond the wall section 37. The least inside width 50 between the free ends is smaller than the inner diameter 44 of the projection 43.

A flange 54, which projects outwardly in the radial direction and which is inserted in the groove 47 of the projection 43 in the assembled state, is formed on that lower front side of the guide component that is turned away from the headrest 1. This forms an undercut between the plug 8 and the guide component 5, which undercut is effective in the direction of the central longitudinal axis 19 or the joining direction 42. The plug 8 is held laterally on the guide component 5 by means of a snap-fit joint, the joining direction 51 of which runs transversely to the central longitudinal axis 19. For this purpose, two detent projections 55 project from the upper side 56 of the wall section 38. These detent projections 55 engage behind the peripheral surface 52 of the flange 54 in the assembled state and form an undercut between the guide component 5 and the plug 8, which undercut is effective transversely to the central longitudinal axis 19 or transversely to the joining direction 42. The detent projections 55 need not be provided with an extremely stable design since the plug 8 is stressed at best only to a small extent in the direction running transversely to the central longitudinal axis 19. Furthermore, the lateral fixation of the plug 8 is enhanced by the fact that the free ends 49 of the projection 43 resiliently engage behind the periphery of the guide component 5. This differs from the case where force is applied in the direction of the central longitudinal axis 19 when inserting the holding rod 3 into the channel 6 of the guide component 5. Here, for example, the socket 7 or its contact sleeves 20, 23 cannot be aligned exactly coaxially due to manufacturing tolerances 8. As a result, a downwardly acting force is exerted on the contact pin 30. However, the undercut formed by the groove 37 [sic; 47] and the flange 54 securely intercepts this force. In order to prevent the plug 8 from being impinged upon by the free end of the holding rod 3 in the case of a larger insertion depth of the holding rod 3 than what is shown in FIG. 5, the diameter 45 of the recess 27 of the plug 8 is dimensioned in such a way that it is slightly larger than the diameter of the free end 10 of the holding rod 3.

LIST OF REFERENCE NUMERALS

-   1 headrest -   2 impact body -   3 holding rod -   4 transverse bar -   5 guide component -   6 channel -   7 socket -   8 plug -   9 cable -   10 free end -   11 backrest -   13 longitudinal section -   14 ribs -   15 region -   16 radial shoulder -   17 front side -   18 recess -   19 central longitudinal axis -   20 contact sleeve -   23 contact sleeve -   24 longitudinal section -   25 longitudinal section -   26 housing -   27 recess -   28 annular wall -   29 base -   30 contact pin -   33 insulating sleeve -   34 contact sleeve -   35 projecting end -   36 cylindrical sleeve -   37 wall section -   38 wall section -   39 height -   40 height -   41 upper side -   42 joining direction -   43 projection -   44 inner diameter -   45 inner diameter -   46 inner wall -   47 groove -   48 side wall -   49 free end -   50 inside width -   51 joining direction -   52 peripheral surface -   53 cable -   54 flange -   55 detent projection -   56 upper side 

1. Headrest system for a vehicle seat, said headrest system comprising a headrest supported by at least one holding rod, a guide component, which can be arrested in the backrest of the vehicle seat and serves for accommodating a holding rod, a first electric connector disposed on the free end of the holding rod and a second electric connector, which cooperates with the first electric connector and can be arrested in the backrest, the joining direction of the two electric connectors running approximately coaxially to the central longitudinal axis of the free end of the holding rod, and each of said two electric connectors comprising at least two contact elements, the contact elements being designed in a rotationally symmetrical manner in relation to the central longitudinal axis or the joining direction.
 2. Headrest system according to claim 1, wherein one connector is designed as a plug and comprises a central contact pin, which extends in the joining direction and penetrates a contact sleeve, which has an electrical insulation on its inner side.
 3. Headrest system according to claim 2, wherein the insulation is designed as a separate insulating sleeve, which is penetrated by the contact pin.
 4. Headrest according to claim 2, wherein the other connector is designed as a socket and comprises a recess, which receives the contact pin and in which are disposed two contact sleeves, which extend coaxially to the joining direction or the central longitudinal axis, are electrically insulated from each other, and cooperate with the contact pin or the contact sleeve of the plug.
 5. Headrest system according to claim 1, wherein a connector assigned to the holding rod is disposed in a hollow space existing in the free end of the holding rod.
 6. Headrest system according to claim 1, wherein a longitudinal section of the connector is provided with a design resembling a ribbed plug.
 7. Headrest system according to claim 1, wherein the connector assigned to the backrest is arrested on that end of the guide component that is turned away from the headrest by means of a snap-fit joint, the joining direction of which runs transversely to the central longitudinal axis and by means of an undercut, which is effective in the direction of the central longitudinal axis.
 8. Headrest system according to claim 7, wherein an undercut element extending transversely to the joining direction is present on the guide component, which undercut element cooperates with a counter element on the connector.
 9. Headrest system according to claim 8, wherein the undercut element and counter element cooperate in such a way that the connector can be arrested in any rotational position on the guide component.
 10. Headrest system according to claim 9, wherein the undercut element is a circular ring-shaped flange, which projects from the peripheral surface of the guide component in the radial direction and the counter element is a groove on the connector, which groove receives the flange.
 11. Headrest system according to claim 7, wherein a snap-fit element is present on that side of the connector that faces the guide component, which snap-fit element engages behind that outer surface of the guide component that runs transversely to the joining direction of the snap-fit joint.
 12. Headrest system according to claim 7, characterized in that a cable laterally leads through the housing of the connector assigned to the backrest. 